Contract cleaners working in London's fire stations will see their hourly wage increase to £7.20 after a vote on the issue.
Ken Livingstone described the vote as a hard-fought victory
The city's Fire and Emergency Planning Authority agreed by nine votes to eight in favour of the minimum hourly rate.
London's Mayor Ken Livingstone described the result as a "hard-fought victory against those who prefer poverty pay to a living wage".
The new rate will also apply to cleaners who work on other premises.
Mr Livingstone said: "The members of the fire authority who voted to apply decent wages to their cleaning staff are to be congratulated, but it shows there is a very sharp dividing line on this issue in London."
Angie Bray, fire authority member for the London Conservatives, insisted she voted against the wage increase because it was not financially viable.
"Of course we support the going rate for the job," she said.
"But it must be remembered that the authority is a mainly grants funded organisation with limited resources.
"Therefore it's obvious in these circumstances that to increase costs in one part of the organisation means taking resources away from others."